docs: def get_mean_and_stddevs(self, sites, rup, dists, imt, stddev_types):
          """
          See :meth:`superclass method
          <.base.GroundShakingIntensityModel.get_mean_and_stddevs>`
          for spec of input and result values.
          """
          # extracting dictionary of coefficients specific to required
          # intensity measure type.
          C = self.COEFFS_ASC[imt]
  
          # mean value as given by equation 1, p. 901, without considering the
          # interface and intraslab terms (that is SI, SS, SSL = 0) and the
          # inter and intra event terms, plus the magnitude-squared term
          # correction factor (equation 5 p. 909).
          mean = self._compute_magnitude_term(C, rup.mag) +\
              self._compute_distance_term(C, rup.mag, dists.rrup) +\
              self._compute_focal_depth_term(C, rup.hypo_depth) +\
              self._compute_faulting_style_term(C, rup.rake) +\
              self._compute_site_class_term(C, sites.vs30) +\
              self._compute_magnitude_squared_term(P=0.0, M=6.3, Q=C['QC'],
                                                   W=C['WC'], mag=rup.mag)
  
          # convert from cm/s**2 to g
          mean = np.log(np.exp(mean) * 1e-2 / g)
  
          stddevs = self._get_stddevs(C['sigma'], C['tauC'], stddev_types,
                                      num_sites=len(sites.vs30))
  
          return mean, stddevs